The Syrian army has reinforced its anti-aircraft defenses near the frontier with Israel، a commander in the regional alliance that backs President Bashar Assad said on Tuesday، as Ynet said. Additional defenses are set to be deployed in the coming days، the commander told Reuters. The stationing of the Russian-made Pantsir S1 weapon aims "to renew the air defense system against Israel in the first degree،" added the commander، a non-Syrian who spoke on condition of anonymity. Syria's multi-sided war has pivoted towards the southwest in recent weeks، risking escalation in an area of major concern to Israel where the conflict has been contained since last year by an agreement underwritten by the United States and Russia. Last month، Iranian forces launched a rocket salvo across the frontier، triggering ferocious air strikes into Syria against Iran-backed positions. The Syrian government has separately been preparing an assault on rebels who hold territory at the border with Israel and Jordan. This led Washington last month to warn of "firm and appropriate measures" against any ceasefire violations. The commander said preparations for the government offensive in the southwest were complete but government forces were now working to finish off a pocket of Islamic State militants near the government-held town of Sweida. Israel wants Iran-backed forces such as Lebanon's Hezbollah kept away from its frontier and removed from Syria more widely. Hezbollah leader Sayyed Hassan Nasrallah said last week the group would stay in Syria as long as Assad wanted it there.